/**
 * 根据传入的日期格式字符串，返回特定日期
 * @param {string} rule - 日期格式字符串
 */
function getDate(rule) {    
    var fixZero = fmtStr.fixPreZero;

    var date = new Date(),
        ruleTemp = {
            y: date.getFullYear(),
            M: fixZero(date.getMonth() + 1),
            d: fixZero(date.getDate()),
            h: fixZero(date.getHours()),
            m: fixZero(date.getMinutes()),
            s: fixZero(date.getSeconds())
        };

    if (rule && typeof rule === 'string') {
        for (var key in ruleTemp) {
            if (ruleTemp.hasOwnProperty(key)) {
                rule = rule.replace(key, ruleTemp[key]);
            }
        }
    } else {
        rule = [ruleTemp.y, ruleTemp.M, ruleTemp.d];
        rule = rule.join('-');
    }

    return rule;
}